The present invention relates to an apparatus and method for treating or preventing a disease process in a luminal structure such as a blood vessel.
Various devices have been proposed and used for angioplasty and restenosis in a luminal structure, such as a vein or artery of a patient. Typically, angioplasty is performed using a balloon catheter. After angioplasty, restenosis can develop in the luminal structure. Balloon injury of the luminal structure, caused by balloon inflation, treated with sublethal doses of radiation stimulates cell proliferation and decreases restenosis. Preliminary information from human trials has indicated that restenosis is inhibited by doses of radioactive isotopes, e.g., of 15-45 Gy, to the wall of the luminal structure. Radioisotopes have been used to treat restenosis, such as by inflating the balloon with a fluid containing a radioisotope.
Human studies suggest that a problem with decreased radiation dose occurs at the edge of the balloon treatment zone, where a combination of subtherapeutic radiation doses combine with balloon or stent trauma to stimulate neointimal proliferation.
It is an object of the present invention to provide an apparatus and method for providing temporal control of radioactive doses in treating or preventing restenosis.
It is an object of the present invention to provide spatial control of radioactive doses in treating or preventing restenosis.
It is an object of the present invention to provide differential temporal and spatial control of radioactive doses in treating or preventing restenosis.
It is an object of the present invention to minimize arterial trauma from vascular angioplasty devices such as balloons in the region of subtherapeutic dose delivered.
It is an object of the present invention to provide an apparatus and method for mitigating injury in the luminal structure of a patient in areas of diminished radiation dose.
It is an object of the present invention to provide an apparatus capable of spatially varying the deliverable dose of radiation, including, for example, providing an increased dose or boost of radiation on the edges relative to the middle.
It is an object of the present invention to provide a catheter having a multi-segmented radiation dose delivery structure, such as a balloon.
As used herein, the term xe2x80x9ctreatingxe2x80x9d or xe2x80x9ctreatmentxe2x80x9d includes treating or treatment of a disease process as well as preventing or inhibiting a disease process. As used herein, the term xe2x80x9cvicinityxe2x80x9d in connection with a luminal structure, includes in the luminal structure and near the luminal structure.
According to one aspect of the invention, an apparatus for treating a disease process in the vicinity of a luminal structure is provided, comprising a catheter shaft, and a radioactive material carrier providing a spatially varying radioactivity along the length of the shaft.
In accordance with another aspect of the present invention, an apparatus for treating a disease process in the vicinity of a luminal structure is provided, comprising a catheter shaft having at least first and second inflation lumens defined longitudinally therein, a first balloon mounted on said shaft and in fluid communication with the first inflation lumen, and a second balloon mounted on said shaft at a different longitudinal position from said first balloon and in fluid communication with the second inflation lumen, to thereby allow separate inflation and deflation of said first and second balloon segments.
According to another aspect of the invention, an apparatus is provided for treating a disease process in the vicinity a luminal structure, comprising a catheter shaft having at least first and second inflation lumens defined longitudinally therein a central balloon mounted on said shaft and in fluid communication with the first inflation lumen and two edge balloons mounted on said shaft on either side of the central balloon, both edge balloons being in fluid communication with the second inflation lumen.
According to another aspect of the invention, a method for treating a disease process in the vicinity of a luminal structure is provided, comprising positioning inside a luminal structure a source of radioactive material having spatially varying distribution, and removing the source of radioactive material after a treatment period.
According to another aspect of the invention, a method for treating a disease process in the vicinity of a luminal structure is provided, comprising providing a balloon catheter having at least two separably inflatable balloons mounted on a catheter shaft at different longitudinally positions on the shaft, inserting the balloon catheter into the luminal structure of a subject, inflating the two balloons separately with radioactive fluid, removing the respective radioactive fluid from the two balloons and removing the balloon catheter from the luminal structure.
According to another aspect of the invention, a method for treating a disease process in the vicinity of a luminal structure is provided, comprising providing a balloon catheter having at least three inflatable balloons mounted on a catheter shaft at different longitudinally positions on the shaft, including a middle balloon and two side balloons at opposite sides of the middle balloon, inserting the balloon catheter into the luminal structure of a subject, inflating the balloons with radioactive fluid by inflating the middle balloon separately from the two side balloons, removing the radioactive fluid from the middle balloon and two side balloons and removing the balloon catheter from the luminal structure.